16 * The standard user interface for Net simply has left- and
17 * right-button mouse clicks in a square rotate it one way or the
18 * other. We also provide, by #ifdef, a separate interface based on
19 * rotational dragging motions. I initially developed this for the
20 * Mac on the basis that it might work better than the click
21 * interface with only one mouse button available, but in fact
22 * found it to be quite strange and unintuitive. Apparently it
23 * works better on stylus-driven platforms such as Palm and
24 * PocketPC, though, so we enable it by default there.
30 #define MATMUL(xr,yr,m,x,y) do { \
31 float rx, ry, xx = (x), yy = (y), *mat = (m); \
32 rx = mat[0] * xx + mat[2] * yy; \
33 ry = mat[1] * xx + mat[3] * yy; \
34 (xr) = rx; (yr) = ry; \
37 /* Direction and other bitfields */
44 #define RLOOP (R << 6)
45 #define ULOOP (U << 6)
46 #define LLOOP (L << 6)
47 #define DLOOP (D << 6)
48 #define LOOP(dir) ((dir) << 6)
50 /* Rotations: Anticlockwise, Clockwise, Flip, general rotate */
51 #define A(x) ( (((x) & 0x07) << 1) | (((x) & 0x08) >> 3) )
52 #define C(x) ( (((x) & 0x0E) >> 1) | (((x) & 0x01) << 3) )
53 #define F(x) ( (((x) & 0x0C) >> 2) | (((x) & 0x03) << 2) )
54 #define ROT(x, n) ( ((n)&3) == 0 ? (x) : \
55 ((n)&3) == 1 ? A(x) : \
56 ((n)&3) == 2 ? F(x) : C(x) )
58 /* X and Y displacements */
59 #define X(x) ( (x) == R ? +1 : (x) == L ? -1 : 0 )
60 #define Y(x) ( (x) == D ? +1 : (x) == U ? -1 : 0 )
63 #define COUNT(x) ( (((x) & 0x08) >> 3) + (((x) & 0x04) >> 2) + \
64 (((x) & 0x02) >> 1) + ((x) & 0x01) )
66 #define PREFERRED_TILE_SIZE 32
67 #define TILE_SIZE (ds->tilesize)
70 #define WINDOW_OFFSET 4
72 #define WINDOW_OFFSET 16
75 #define ROTATE_TIME 0.13F
76 #define FLASH_FRAME 0.07F
78 /* Transform physical coords to game coords using game_drawstate ds */
79 #define GX(x) (((x) + ds->org_x) % ds->width)
80 #define GY(y) (((y) + ds->org_y) % ds->height)
81 /* ...and game coords to physical coords */
82 #define RX(x) (((x) + ds->width - ds->org_x) % ds->width)
83 #define RY(y) (((y) + ds->height - ds->org_y) % ds->height)
102 float barrier_probability;
106 int width, height, wrapping, completed;
107 int last_rotate_x, last_rotate_y, last_rotate_dir;
109 unsigned char *tiles;
110 unsigned char *barriers;
113 #define OFFSETWH(x2,y2,x1,y1,dir,width,height) \
114 ( (x2) = ((x1) + width + X((dir))) % width, \
115 (y2) = ((y1) + height + Y((dir))) % height)
117 #define OFFSET(x2,y2,x1,y1,dir,state) \
118 OFFSETWH(x2,y2,x1,y1,dir,(state)->width,(state)->height)
120 #define index(state, a, x, y) ( a[(y) * (state)->width + (x)] )
121 #define tile(state, x, y) index(state, (state)->tiles, x, y)
122 #define barrier(state, x, y) index(state, (state)->barriers, x, y)
128 static int xyd_cmp(const void *av, const void *bv) {
129 const struct xyd *a = (const struct xyd *)av;
130 const struct xyd *b = (const struct xyd *)bv;
139 if (a->direction < b->direction)
141 if (a->direction > b->direction)
146 static int xyd_cmp_nc(void *av, void *bv) { return xyd_cmp(av, bv); }
148 static struct xyd *new_xyd(int x, int y, int direction)
150 struct xyd *xyd = snew(struct xyd);
153 xyd->direction = direction;
157 /* ----------------------------------------------------------------------
158 * Manage game parameters.
160 static game_params *default_params(void)
162 game_params *ret = snew(game_params);
166 ret->wrapping = FALSE;
168 ret->barrier_probability = 0.0;
173 static const struct game_params net_presets[] = {
174 {5, 5, FALSE, TRUE, 0.0},
175 {7, 7, FALSE, TRUE, 0.0},
176 {9, 9, FALSE, TRUE, 0.0},
177 {11, 11, FALSE, TRUE, 0.0},
179 {13, 11, FALSE, TRUE, 0.0},
181 {5, 5, TRUE, TRUE, 0.0},
182 {7, 7, TRUE, TRUE, 0.0},
183 {9, 9, TRUE, TRUE, 0.0},
184 {11, 11, TRUE, TRUE, 0.0},
186 {13, 11, TRUE, TRUE, 0.0},
190 static int game_fetch_preset(int i, char **name, game_params **params)
195 if (i < 0 || i >= lenof(net_presets))
198 ret = snew(game_params);
199 *ret = net_presets[i];
201 sprintf(str, "%dx%d%s", ret->width, ret->height,
202 ret->wrapping ? " wrapping" : "");
209 static void free_params(game_params *params)
214 static game_params *dup_params(const game_params *params)
216 game_params *ret = snew(game_params);
217 *ret = *params; /* structure copy */
221 static void decode_params(game_params *ret, char const *string)
223 char const *p = string;
225 ret->width = atoi(p);
226 while (*p && isdigit((unsigned char)*p)) p++;
229 ret->height = atoi(p);
230 while (*p && isdigit((unsigned char)*p)) p++;
232 ret->height = ret->width;
238 ret->wrapping = TRUE;
239 } else if (*p == 'b') {
241 ret->barrier_probability = (float)atof(p);
242 while (*p && (*p == '.' || isdigit((unsigned char)*p))) p++;
243 } else if (*p == 'a') {
247 p++; /* skip any other gunk */
251 static char *encode_params(const game_params *params, int full)
256 len = sprintf(ret, "%dx%d", params->width, params->height);
257 if (params->wrapping)
259 if (full && params->barrier_probability)
260 len += sprintf(ret+len, "b%g", params->barrier_probability);
261 if (full && !params->unique)
263 assert(len < lenof(ret));
269 static config_item *game_configure(const game_params *params)
274 ret = snewn(6, config_item);
276 ret[0].name = "Width";
277 ret[0].type = C_STRING;
278 sprintf(buf, "%d", params->width);
279 ret[0].sval = dupstr(buf);
282 ret[1].name = "Height";
283 ret[1].type = C_STRING;
284 sprintf(buf, "%d", params->height);
285 ret[1].sval = dupstr(buf);
288 ret[2].name = "Walls wrap around";
289 ret[2].type = C_BOOLEAN;
291 ret[2].ival = params->wrapping;
293 ret[3].name = "Barrier probability";
294 ret[3].type = C_STRING;
295 sprintf(buf, "%g", params->barrier_probability);
296 ret[3].sval = dupstr(buf);
299 ret[4].name = "Ensure unique solution";
300 ret[4].type = C_BOOLEAN;
302 ret[4].ival = params->unique;
312 static game_params *custom_params(const config_item *cfg)
314 game_params *ret = snew(game_params);
316 ret->width = atoi(cfg[0].sval);
317 ret->height = atoi(cfg[1].sval);
318 ret->wrapping = cfg[2].ival;
319 ret->barrier_probability = (float)atof(cfg[3].sval);
320 ret->unique = cfg[4].ival;
325 static char *validate_params(const game_params *params, int full)
327 if (params->width <= 0 || params->height <= 0)
328 return "Width and height must both be greater than zero";
329 if (params->width <= 1 && params->height <= 1)
330 return "At least one of width and height must be greater than one";
331 if (params->barrier_probability < 0)
332 return "Barrier probability may not be negative";
333 if (params->barrier_probability > 1)
334 return "Barrier probability may not be greater than 1";
337 * Specifying either grid dimension as 2 in a wrapping puzzle
338 * makes it actually impossible to ensure a unique puzzle
343 * Without loss of generality, let us assume the puzzle _width_
344 * is 2, so we can conveniently discuss rows without having to
345 * say `rows/columns' all the time. (The height may be 2 as
346 * well, but that doesn't matter.)
348 * In each row, there are two edges between tiles: the inner
349 * edge (running down the centre of the grid) and the outer
350 * edge (the identified left and right edges of the grid).
352 * Lemma: In any valid 2xn puzzle there must be at least one
353 * row in which _exactly one_ of the inner edge and outer edge
356 * Proof: No row can have _both_ inner and outer edges
357 * connected, because this would yield a loop. So the only
358 * other way to falsify the lemma is for every row to have
359 * _neither_ the inner nor outer edge connected. But this
360 * means there is no connection at all between the left and
361 * right columns of the puzzle, so there are two disjoint
362 * subgraphs, which is also disallowed. []
364 * Given such a row, it is always possible to make the
365 * disconnected edge connected and the connected edge
366 * disconnected without changing the state of any other edge.
367 * (This is easily seen by case analysis on the various tiles:
368 * left-pointing and right-pointing endpoints can be exchanged,
369 * likewise T-pieces, and a corner piece can select its
370 * horizontal connectivity independently of its vertical.) This
371 * yields a distinct valid solution.
373 * Thus, for _every_ row in which exactly one of the inner and
374 * outer edge is connected, there are two valid states for that
375 * row, and hence the total number of solutions of the puzzle
376 * is at least 2^(number of such rows), and in particular is at
377 * least 2 since there must be at least one such row. []
379 if (full && params->unique && params->wrapping &&
380 (params->width == 2 || params->height == 2))
381 return "No wrapping puzzle with a width or height of 2 can have"
382 " a unique solution";
387 /* ----------------------------------------------------------------------
388 * Solver used to assure solution uniqueness during generation.
392 * Test cases I used while debugging all this were
394 * ./net --generate 1 13x11w#12300
395 * which expands under the non-unique grid generation rules to
396 * 13x11w:5eaade1bd222664436d5e2965c12656b1129dd825219e3274d558d5eb2dab5da18898e571d5a2987be79746bd95726c597447d6da96188c513add829da7681da954db113d3cd244
397 * and has two ambiguous areas.
399 * An even better one is
400 * 13x11w#507896411361192
402 * 13x11w:b7125b1aec598eb31bd58d82572bc11494e5dee4e8db2bdd29b88d41a16bdd996d2996ddec8c83741a1e8674e78328ba71737b8894a9271b1cd1399453d1952e43951d9b712822e
403 * and has an ambiguous area _and_ a situation where loop avoidance
404 * is a necessary deductive technique.
407 * 48x25w#820543338195187
409 * 48x25w:255989d14cdd185deaa753a93821a12edc1ab97943ac127e2685d7b8b3c48861b2192416139212b316eddd35de43714ebc7628d753db32e596284d9ec52c5a7dc1b4c811a655117d16dc28921b2b4161352cab1d89d18bc836b8b891d55ea4622a1251861b5bc9a8aa3e5bcd745c95229ca6c3b5e21d5832d397e917325793d7eb442dc351b2db2a52ba8e1651642275842d8871d5534aabc6d5b741aaa2d48ed2a7dbbb3151ddb49d5b9a7ed1ab98ee75d613d656dbba347bc514c84556b43a9bc65a3256ead792488b862a9d2a8a39b4255a4949ed7dbd79443292521265896b4399c95ede89d7c8c797a6a57791a849adea489359a158aa12e5dacce862b8333b7ebea7d344d1a3c53198864b73a9dedde7b663abb1b539e1e8853b1b7edb14a2a17ebaae4dbe63598a2e7e9a2dbdad415bc1d8cb88cbab5a8c82925732cd282e641ea3bd7d2c6e776de9117a26be86deb7c82c89524b122cb9397cd1acd2284e744ea62b9279bae85479ababe315c3ac29c431333395b24e6a1e3c43a2da42d4dce84aadd5b154aea555eaddcbd6e527d228c19388d9b424d94214555a7edbdeebe569d4a56dc51a86bd9963e377bb74752bd5eaa5761ba545e297b62a1bda46ab4aee423ad6c661311783cc18786d4289236563cb4a75ec67d481c14814994464cd1b87396dee63e5ab6e952cc584baa1d4c47cb557ec84dbb63d487c8728118673a166846dd3a4ebc23d6cb9c5827d96b4556e91899db32b517eda815ae271a8911bd745447121dc8d321557bc2a435ebec1bbac35b1a291669451174e6aa2218a4a9c5a6ca31ebc45d84e3a82c121e9ced7d55e9a
410 * which has a spot (far right) where slightly more complex loop
411 * avoidance is required.
415 unsigned char *marked;
421 static struct todo *todo_new(int maxsize)
423 struct todo *todo = snew(struct todo);
424 todo->marked = snewn(maxsize, unsigned char);
425 memset(todo->marked, 0, maxsize);
426 todo->buflen = maxsize + 1;
427 todo->buffer = snewn(todo->buflen, int);
428 todo->head = todo->tail = 0;
432 static void todo_free(struct todo *todo)
439 static void todo_add(struct todo *todo, int index)
441 if (todo->marked[index])
442 return; /* already on the list */
443 todo->marked[index] = TRUE;
444 todo->buffer[todo->tail++] = index;
445 if (todo->tail == todo->buflen)
449 static int todo_get(struct todo *todo) {
452 if (todo->head == todo->tail)
453 return -1; /* list is empty */
454 ret = todo->buffer[todo->head++];
455 if (todo->head == todo->buflen)
457 todo->marked[ret] = FALSE;
463 * Return values: -1 means puzzle was proved inconsistent, 0 means we
464 * failed to narrow down to a unique solution, +1 means we solved it
467 static int net_solver(int w, int h, unsigned char *tiles,
468 unsigned char *barriers, int wrapping)
470 unsigned char *tilestate;
471 unsigned char *edgestate;
480 * Set up the solver's data structures.
484 * tilestate stores the possible orientations of each tile.
485 * There are up to four of these, so we'll index the array in
486 * fours. tilestate[(y * w + x) * 4] and its three successive
487 * members give the possible orientations, clearing to 255 from
488 * the end as things are ruled out.
490 * In this loop we also count up the area of the grid (which is
491 * not _necessarily_ equal to w*h, because there might be one
492 * or more blank squares present. This will never happen in a
493 * grid generated _by_ this program, but it's worth keeping the
494 * solver as general as possible.)
496 tilestate = snewn(w * h * 4, unsigned char);
498 for (i = 0; i < w*h; i++) {
499 tilestate[i * 4] = tiles[i] & 0xF;
500 for (j = 1; j < 4; j++) {
501 if (tilestate[i * 4 + j - 1] == 255 ||
502 A(tilestate[i * 4 + j - 1]) == tilestate[i * 4])
503 tilestate[i * 4 + j] = 255;
505 tilestate[i * 4 + j] = A(tilestate[i * 4 + j - 1]);
512 * edgestate stores the known state of each edge. It is 0 for
513 * unknown, 1 for open (connected) and 2 for closed (not
516 * In principle we need only worry about each edge once each,
517 * but in fact it's easier to track each edge twice so that we
518 * can reference it from either side conveniently. Also I'm
519 * going to allocate _five_ bytes per tile, rather than the
520 * obvious four, so that I can index edgestate[(y*w+x) * 5 + d]
521 * where d is 1,2,4,8 and they never overlap.
523 edgestate = snewn((w * h - 1) * 5 + 9, unsigned char);
524 memset(edgestate, 0, (w * h - 1) * 5 + 9);
527 * deadends tracks which edges have dead ends on them. It is
528 * indexed by tile and direction: deadends[(y*w+x) * 5 + d]
529 * tells you whether heading out of tile (x,y) in direction d
530 * can reach a limited amount of the grid. Values are area+1
531 * (no dead end known) or less than that (can reach _at most_
532 * this many other tiles by heading this way out of this tile).
534 deadends = snewn((w * h - 1) * 5 + 9, int);
535 for (i = 0; i < (w * h - 1) * 5 + 9; i++)
536 deadends[i] = area+1;
539 * equivalence tracks which sets of tiles are known to be
540 * connected to one another, so we can avoid creating loops by
541 * linking together tiles which are already linked through
544 * This is a disjoint set forest structure: equivalence[i]
545 * contains the index of another member of the equivalence
546 * class containing i, or contains i itself for precisely one
547 * member in each such class. To find a representative member
548 * of the equivalence class containing i, you keep replacing i
549 * with equivalence[i] until it stops changing; then you go
550 * _back_ along the same path and point everything on it
551 * directly at the representative member so as to speed up
552 * future searches. Then you test equivalence between tiles by
553 * finding the representative of each tile and seeing if
554 * they're the same; and you create new equivalence (merge
555 * classes) by finding the representative of each tile and
556 * setting equivalence[one]=the_other.
558 equivalence = snew_dsf(w * h);
561 * On a non-wrapping grid, we instantly know that all the edges
562 * round the edge are closed.
565 for (i = 0; i < w; i++) {
566 edgestate[i * 5 + 2] = edgestate[((h-1) * w + i) * 5 + 8] = 2;
568 for (i = 0; i < h; i++) {
569 edgestate[(i * w + w-1) * 5 + 1] = edgestate[(i * w) * 5 + 4] = 2;
574 * If we have barriers available, we can mark those edges as
578 for (y = 0; y < h; y++) for (x = 0; x < w; x++) {
580 for (d = 1; d <= 8; d += d) {
581 if (barriers[y*w+x] & d) {
584 * In principle the barrier list should already
585 * contain each barrier from each side, but
586 * let's not take chances with our internal
589 OFFSETWH(x2, y2, x, y, d, w, h);
590 edgestate[(y*w+x) * 5 + d] = 2;
591 edgestate[(y2*w+x2) * 5 + F(d)] = 2;
598 * Since most deductions made by this solver are local (the
599 * exception is loop avoidance, where joining two tiles
600 * together on one side of the grid can theoretically permit a
601 * fresh deduction on the other), we can address the scaling
602 * problem inherent in iterating repeatedly over the entire
603 * grid by instead working with a to-do list.
605 todo = todo_new(w * h);
608 * Main deductive loop.
610 done_something = TRUE; /* prevent instant termination! */
615 * Take a tile index off the todo list and process it.
617 index = todo_get(todo);
620 * If we have run out of immediate things to do, we
621 * have no choice but to scan the whole grid for
622 * longer-range things we've missed. Hence, I now add
623 * every square on the grid back on to the to-do list.
624 * I also set `done_something' to FALSE at this point;
625 * if we later come back here and find it still FALSE,
626 * we will know we've scanned the entire grid without
627 * finding anything new to do, and we can terminate.
631 for (i = 0; i < w*h; i++)
633 done_something = FALSE;
635 index = todo_get(todo);
641 int d, ourclass = dsf_canonify(equivalence, y*w+x);
644 deadendmax[1] = deadendmax[2] = deadendmax[4] = deadendmax[8] = 0;
646 for (i = j = 0; i < 4 && tilestate[(y*w+x) * 4 + i] != 255; i++) {
648 int nnondeadends, nondeadends[4], deadendtotal;
649 int nequiv, equiv[5];
650 int val = tilestate[(y*w+x) * 4 + i];
653 nnondeadends = deadendtotal = 0;
656 for (d = 1; d <= 8; d += d) {
658 * Immediately rule out this orientation if it
659 * conflicts with any known edge.
661 if ((edgestate[(y*w+x) * 5 + d] == 1 && !(val & d)) ||
662 (edgestate[(y*w+x) * 5 + d] == 2 && (val & d)))
667 * Count up the dead-end statistics.
669 if (deadends[(y*w+x) * 5 + d] <= area) {
670 deadendtotal += deadends[(y*w+x) * 5 + d];
672 nondeadends[nnondeadends++] = d;
676 * Ensure we aren't linking to any tiles,
677 * through edges not already known to be
678 * open, which create a loop.
680 if (edgestate[(y*w+x) * 5 + d] == 0) {
683 OFFSETWH(x2, y2, x, y, d, w, h);
684 c = dsf_canonify(equivalence, y2*w+x2);
685 for (k = 0; k < nequiv; k++)
696 if (nnondeadends == 0) {
698 * If this orientation links together dead-ends
699 * with a total area of less than the entire
700 * grid, it is invalid.
702 * (We add 1 to deadendtotal because of the
703 * tile itself, of course; one tile linking
704 * dead ends of size 2 and 3 forms a subnetwork
705 * with a total area of 6, not 5.)
707 if (deadendtotal > 0 && deadendtotal+1 < area)
709 } else if (nnondeadends == 1) {
711 * If this orientation links together one or
712 * more dead-ends with precisely one
713 * non-dead-end, then we may have to mark that
714 * non-dead-end as a dead end going the other
715 * way. However, it depends on whether all
716 * other orientations share the same property.
719 if (deadendmax[nondeadends[0]] < deadendtotal)
720 deadendmax[nondeadends[0]] = deadendtotal;
723 * If this orientation links together two or
724 * more non-dead-ends, then we can rule out the
725 * possibility of putting in new dead-end
726 * markings in those directions.
729 for (k = 0; k < nnondeadends; k++)
730 deadendmax[nondeadends[k]] = area+1;
734 tilestate[(y*w+x) * 4 + j++] = val;
735 #ifdef SOLVER_DIAGNOSTICS
737 printf("ruling out orientation %x at %d,%d\n", val, x, y);
742 /* If we've ruled out all possible orientations for a
743 * tile, then our puzzle has no solution at all. */
748 done_something = TRUE;
751 * We have ruled out at least one tile orientation.
752 * Make sure the rest are blanked.
755 tilestate[(y*w+x) * 4 + j++] = 255;
759 * Now go through the tile orientations again and see
760 * if we've deduced anything new about any edges.
766 for (i = 0; i < 4 && tilestate[(y*w+x) * 4 + i] != 255; i++) {
767 a &= tilestate[(y*w+x) * 4 + i];
768 o |= tilestate[(y*w+x) * 4 + i];
770 for (d = 1; d <= 8; d += d)
771 if (edgestate[(y*w+x) * 5 + d] == 0) {
773 OFFSETWH(x2, y2, x, y, d, w, h);
776 /* This edge is open in all orientations. */
777 #ifdef SOLVER_DIAGNOSTICS
778 printf("marking edge %d,%d:%d open\n", x, y, d);
780 edgestate[(y*w+x) * 5 + d] = 1;
781 edgestate[(y2*w+x2) * 5 + d2] = 1;
782 dsf_merge(equivalence, y*w+x, y2*w+x2);
783 done_something = TRUE;
784 todo_add(todo, y2*w+x2);
785 } else if (!(o & d)) {
786 /* This edge is closed in all orientations. */
787 #ifdef SOLVER_DIAGNOSTICS
788 printf("marking edge %d,%d:%d closed\n", x, y, d);
790 edgestate[(y*w+x) * 5 + d] = 2;
791 edgestate[(y2*w+x2) * 5 + d2] = 2;
792 done_something = TRUE;
793 todo_add(todo, y2*w+x2);
800 * Now check the dead-end markers and see if any of
801 * them has lowered from the real ones.
803 for (d = 1; d <= 8; d += d) {
805 OFFSETWH(x2, y2, x, y, d, w, h);
807 if (deadendmax[d] > 0 &&
808 deadends[(y2*w+x2) * 5 + d2] > deadendmax[d]) {
809 #ifdef SOLVER_DIAGNOSTICS
810 printf("setting dead end value %d,%d:%d to %d\n",
811 x2, y2, d2, deadendmax[d]);
813 deadends[(y2*w+x2) * 5 + d2] = deadendmax[d];
814 done_something = TRUE;
815 todo_add(todo, y2*w+x2);
823 * Mark all completely determined tiles as locked.
826 for (i = 0; i < w*h; i++) {
827 if (tilestate[i * 4 + 1] == 255) {
828 assert(tilestate[i * 4 + 0] != 255);
829 tiles[i] = tilestate[i * 4] | LOCKED;
837 * Free up working space.
848 /* ----------------------------------------------------------------------
849 * Randomly select a new game description.
853 * Function to randomly perturb an ambiguous section in a grid, to
854 * attempt to ensure unique solvability.
856 static void perturb(int w, int h, unsigned char *tiles, int wrapping,
857 random_state *rs, int startx, int starty, int startd)
859 struct xyd *perimeter, *perim2, *loop[2], looppos[2];
860 int nperim, perimsize, nloop[2], loopsize[2];
864 * We know that the tile at (startx,starty) is part of an
865 * ambiguous section, and we also know that its neighbour in
866 * direction startd is fully specified. We begin by tracing all
867 * the way round the ambiguous area.
869 nperim = perimsize = 0;
874 #ifdef PERTURB_DIAGNOSTICS
875 printf("perturb %d,%d:%d\n", x, y, d);
880 if (nperim >= perimsize) {
881 perimsize = perimsize * 3 / 2 + 32;
882 perimeter = sresize(perimeter, perimsize, struct xyd);
884 perimeter[nperim].x = x;
885 perimeter[nperim].y = y;
886 perimeter[nperim].direction = d;
888 #ifdef PERTURB_DIAGNOSTICS
889 printf("perimeter: %d,%d:%d\n", x, y, d);
893 * First, see if we can simply turn left from where we are
894 * and find another locked square.
897 OFFSETWH(x2, y2, x, y, d2, w, h);
898 if ((!wrapping && (abs(x2-x) > 1 || abs(y2-y) > 1)) ||
899 (tiles[y2*w+x2] & LOCKED)) {
903 * Failing that, step left into the new square and look
908 OFFSETWH(x2, y2, x, y, d, w, h);
909 if ((wrapping || (abs(x2-x) <= 1 && abs(y2-y) <= 1)) &&
910 !(tiles[y2*w+x2] & LOCKED)) {
912 * And failing _that_, we're going to have to step
913 * forward into _that_ square and look right at the
914 * same locked square as we started with.
922 } while (x != startx || y != starty || d != startd);
925 * Our technique for perturbing this ambiguous area is to
926 * search round its edge for a join we can make: that is, an
927 * edge on the perimeter which is (a) not currently connected,
928 * and (b) connecting it would not yield a full cross on either
929 * side. Then we make that join, search round the network to
930 * find the loop thus constructed, and sever the loop at a
931 * randomly selected other point.
933 perim2 = snewn(nperim, struct xyd);
934 memcpy(perim2, perimeter, nperim * sizeof(struct xyd));
935 /* Shuffle the perimeter, so as to search it without directional bias. */
936 shuffle(perim2, nperim, sizeof(*perim2), rs);
937 for (i = 0; i < nperim; i++) {
942 d = perim2[i].direction;
944 OFFSETWH(x2, y2, x, y, d, w, h);
945 if (!wrapping && (abs(x2-x) > 1 || abs(y2-y) > 1))
946 continue; /* can't link across non-wrapping border */
947 if (tiles[y*w+x] & d)
948 continue; /* already linked in this direction! */
949 if (((tiles[y*w+x] | d) & 15) == 15)
950 continue; /* can't turn this tile into a cross */
951 if (((tiles[y2*w+x2] | F(d)) & 15) == 15)
952 continue; /* can't turn other tile into a cross */
955 * We've found the point at which we're going to make a new
958 #ifdef PERTURB_DIAGNOSTICS
959 printf("linking %d,%d:%d\n", x, y, d);
962 tiles[y2*w+x2] |= F(d);
970 return; /* nothing we can do! */
974 * Now we've constructed a new link, we need to find the entire
975 * loop of which it is a part.
977 * In principle, this involves doing a complete search round
978 * the network. However, I anticipate that in the vast majority
979 * of cases the loop will be quite small, so what I'm going to
980 * do is make _two_ searches round the network in parallel, one
981 * keeping its metaphorical hand on the left-hand wall while
982 * the other keeps its hand on the right. As soon as one of
983 * them gets back to its starting point, I abandon the other.
985 for (i = 0; i < 2; i++) {
986 loopsize[i] = nloop[i] = 0;
990 looppos[i].direction = d;
993 for (i = 0; i < 2; i++) {
998 d = looppos[i].direction;
1000 OFFSETWH(x2, y2, x, y, d, w, h);
1003 * Add this path segment to the loop, unless it exactly
1004 * reverses the previous one on the loop in which case
1005 * we take it away again.
1007 #ifdef PERTURB_DIAGNOSTICS
1008 printf("looppos[%d] = %d,%d:%d\n", i, x, y, d);
1011 loop[i][nloop[i]-1].x == x2 &&
1012 loop[i][nloop[i]-1].y == y2 &&
1013 loop[i][nloop[i]-1].direction == F(d)) {
1014 #ifdef PERTURB_DIAGNOSTICS
1015 printf("removing path segment %d,%d:%d from loop[%d]\n",
1020 if (nloop[i] >= loopsize[i]) {
1021 loopsize[i] = loopsize[i] * 3 / 2 + 32;
1022 loop[i] = sresize(loop[i], loopsize[i], struct xyd);
1024 #ifdef PERTURB_DIAGNOSTICS
1025 printf("adding path segment %d,%d:%d to loop[%d]\n",
1028 loop[i][nloop[i]++] = looppos[i];
1031 #ifdef PERTURB_DIAGNOSTICS
1032 printf("tile at new location is %x\n", tiles[y2*w+x2] & 0xF);
1035 for (j = 0; j < 4; j++) {
1040 #ifdef PERTURB_DIAGNOSTICS
1041 printf("trying dir %d\n", d);
1043 if (tiles[y2*w+x2] & d) {
1046 looppos[i].direction = d;
1052 assert(nloop[i] > 0);
1054 if (looppos[i].x == loop[i][0].x &&
1055 looppos[i].y == loop[i][0].y &&
1056 looppos[i].direction == loop[i][0].direction) {
1057 #ifdef PERTURB_DIAGNOSTICS
1058 printf("loop %d finished tracking\n", i);
1062 * Having found our loop, we now sever it at a
1063 * randomly chosen point - absolutely any will do -
1064 * which is not the one we joined it at to begin
1065 * with. Conveniently, the one we joined it at is
1066 * loop[i][0], so we just avoid that one.
1068 j = random_upto(rs, nloop[i]-1) + 1;
1071 d = loop[i][j].direction;
1072 OFFSETWH(x2, y2, x, y, d, w, h);
1074 tiles[y2*w+x2] &= ~F(d);
1086 * Finally, we must mark the entire disputed section as locked,
1087 * to prevent the perturb function being called on it multiple
1090 * To do this, we _sort_ the perimeter of the area. The
1091 * existing xyd_cmp function will arrange things into columns
1092 * for us, in such a way that each column has the edges in
1093 * vertical order. Then we can work down each column and fill
1094 * in all the squares between an up edge and a down edge.
1096 qsort(perimeter, nperim, sizeof(struct xyd), xyd_cmp);
1098 for (i = 0; i <= nperim; i++) {
1099 if (i == nperim || perimeter[i].x > x) {
1101 * Fill in everything from the last Up edge to the
1102 * bottom of the grid, if necessary.
1106 #ifdef PERTURB_DIAGNOSTICS
1107 printf("resolved: locking tile %d,%d\n", x, y);
1109 tiles[y * w + x] |= LOCKED;
1122 if (perimeter[i].direction == U) {
1125 } else if (perimeter[i].direction == D) {
1127 * Fill in everything from the last Up edge to here.
1129 assert(x == perimeter[i].x && y <= perimeter[i].y);
1130 while (y <= perimeter[i].y) {
1131 #ifdef PERTURB_DIAGNOSTICS
1132 printf("resolved: locking tile %d,%d\n", x, y);
1134 tiles[y * w + x] |= LOCKED;
1144 static int *compute_loops_inner(int w, int h, int wrapping,
1145 const unsigned char *tiles,
1146 const unsigned char *barriers);
1148 static char *new_game_desc(const game_params *params, random_state *rs,
1149 char **aux, int interactive)
1151 tree234 *possibilities, *barriertree;
1152 int w, h, x, y, cx, cy, nbarriers;
1153 unsigned char *tiles, *barriers;
1162 tiles = snewn(w * h, unsigned char);
1163 barriers = snewn(w * h, unsigned char);
1167 memset(tiles, 0, w * h);
1168 memset(barriers, 0, w * h);
1171 * Construct the unshuffled grid.
1173 * To do this, we simply start at the centre point, repeatedly
1174 * choose a random possibility out of the available ways to
1175 * extend a used square into an unused one, and do it. After
1176 * extending the third line out of a square, we remove the
1177 * fourth from the possibilities list to avoid any full-cross
1178 * squares (which would make the game too easy because they
1179 * only have one orientation).
1181 * The slightly worrying thing is the avoidance of full-cross
1182 * squares. Can this cause our unsophisticated construction
1183 * algorithm to paint itself into a corner, by getting into a
1184 * situation where there are some unreached squares and the
1185 * only way to reach any of them is to extend a T-piece into a
1188 * Answer: no it can't, and here's a proof.
1190 * Any contiguous group of such unreachable squares must be
1191 * surrounded on _all_ sides by T-pieces pointing away from the
1192 * group. (If not, then there is a square which can be extended
1193 * into one of the `unreachable' ones, and so it wasn't
1194 * unreachable after all.) In particular, this implies that
1195 * each contiguous group of unreachable squares must be
1196 * rectangular in shape (any deviation from that yields a
1197 * non-T-piece next to an `unreachable' square).
1199 * So we have a rectangle of unreachable squares, with T-pieces
1200 * forming a solid border around the rectangle. The corners of
1201 * that border must be connected (since every tile connects all
1202 * the lines arriving in it), and therefore the border must
1203 * form a closed loop around the rectangle.
1205 * But this can't have happened in the first place, since we
1206 * _know_ we've avoided creating closed loops! Hence, no such
1207 * situation can ever arise, and the naive grid construction
1208 * algorithm will guaranteeably result in a complete grid
1209 * containing no unreached squares, no full crosses _and_ no
1212 possibilities = newtree234(xyd_cmp_nc);
1215 add234(possibilities, new_xyd(cx, cy, R));
1217 add234(possibilities, new_xyd(cx, cy, U));
1219 add234(possibilities, new_xyd(cx, cy, L));
1221 add234(possibilities, new_xyd(cx, cy, D));
1223 while (count234(possibilities) > 0) {
1226 int x1, y1, d1, x2, y2, d2, d;
1229 * Extract a randomly chosen possibility from the list.
1231 i = random_upto(rs, count234(possibilities));
1232 xyd = delpos234(possibilities, i);
1235 d1 = xyd->direction;
1238 OFFSET(x2, y2, x1, y1, d1, params);
1240 #ifdef GENERATION_DIAGNOSTICS
1241 printf("picked (%d,%d,%c) <-> (%d,%d,%c)\n",
1242 x1, y1, "0RU3L567D9abcdef"[d1], x2, y2, "0RU3L567D9abcdef"[d2]);
1246 * Make the connection. (We should be moving to an as yet
1249 index(params, tiles, x1, y1) |= d1;
1250 assert(index(params, tiles, x2, y2) == 0);
1251 index(params, tiles, x2, y2) |= d2;
1254 * If we have created a T-piece, remove its last
1257 if (COUNT(index(params, tiles, x1, y1)) == 3) {
1258 struct xyd xyd1, *xydp;
1262 xyd1.direction = 0x0F ^ index(params, tiles, x1, y1);
1264 xydp = find234(possibilities, &xyd1, NULL);
1267 #ifdef GENERATION_DIAGNOSTICS
1268 printf("T-piece; removing (%d,%d,%c)\n",
1269 xydp->x, xydp->y, "0RU3L567D9abcdef"[xydp->direction]);
1271 del234(possibilities, xydp);
1277 * Remove all other possibilities that were pointing at the
1278 * tile we've just moved into.
1280 for (d = 1; d < 0x10; d <<= 1) {
1282 struct xyd xyd1, *xydp;
1284 OFFSET(x3, y3, x2, y2, d, params);
1289 xyd1.direction = d3;
1291 xydp = find234(possibilities, &xyd1, NULL);
1294 #ifdef GENERATION_DIAGNOSTICS
1295 printf("Loop avoidance; removing (%d,%d,%c)\n",
1296 xydp->x, xydp->y, "0RU3L567D9abcdef"[xydp->direction]);
1298 del234(possibilities, xydp);
1304 * Add new possibilities to the list for moving _out_ of
1305 * the tile we have just moved into.
1307 for (d = 1; d < 0x10; d <<= 1) {
1311 continue; /* we've got this one already */
1313 if (!params->wrapping) {
1314 if (d == U && y2 == 0)
1316 if (d == D && y2 == h-1)
1318 if (d == L && x2 == 0)
1320 if (d == R && x2 == w-1)
1324 OFFSET(x3, y3, x2, y2, d, params);
1326 if (index(params, tiles, x3, y3))
1327 continue; /* this would create a loop */
1329 #ifdef GENERATION_DIAGNOSTICS
1330 printf("New frontier; adding (%d,%d,%c)\n",
1331 x2, y2, "0RU3L567D9abcdef"[d]);
1333 add234(possibilities, new_xyd(x2, y2, d));
1336 /* Having done that, we should have no possibilities remaining. */
1337 assert(count234(possibilities) == 0);
1338 freetree234(possibilities);
1340 if (params->unique) {
1344 * Run the solver to check unique solubility.
1346 while (net_solver(w, h, tiles, NULL, params->wrapping) != 1) {
1350 * We expect (in most cases) that most of the grid will
1351 * be uniquely specified already, and the remaining
1352 * ambiguous sections will be small and separate. So
1353 * our strategy is to find each individual such
1354 * section, and perform a perturbation on the network
1357 for (y = 0; y < h; y++) for (x = 0; x < w; x++) {
1358 if (x+1 < w && ((tiles[y*w+x] ^ tiles[y*w+x+1]) & LOCKED)) {
1360 if (tiles[y*w+x] & LOCKED)
1361 perturb(w, h, tiles, params->wrapping, rs, x+1, y, L);
1363 perturb(w, h, tiles, params->wrapping, rs, x, y, R);
1365 if (y+1 < h && ((tiles[y*w+x] ^ tiles[(y+1)*w+x]) & LOCKED)) {
1367 if (tiles[y*w+x] & LOCKED)
1368 perturb(w, h, tiles, params->wrapping, rs, x, y+1, U);
1370 perturb(w, h, tiles, params->wrapping, rs, x, y, D);
1375 * Now n counts the number of ambiguous sections we
1376 * have fiddled with. If we haven't managed to decrease
1377 * it from the last time we ran the solver, give up and
1378 * regenerate the entire grid.
1380 if (prevn != -1 && prevn <= n)
1381 goto begin_generation; /* (sorry) */
1387 * The solver will have left a lot of LOCKED bits lying
1388 * around in the tiles array. Remove them.
1390 for (x = 0; x < w*h; x++)
1391 tiles[x] &= ~LOCKED;
1395 * Now compute a list of the possible barrier locations.
1397 barriertree = newtree234(xyd_cmp_nc);
1398 for (y = 0; y < h; y++) {
1399 for (x = 0; x < w; x++) {
1401 if (!(index(params, tiles, x, y) & R) &&
1402 (params->wrapping || x < w-1))
1403 add234(barriertree, new_xyd(x, y, R));
1404 if (!(index(params, tiles, x, y) & D) &&
1405 (params->wrapping || y < h-1))
1406 add234(barriertree, new_xyd(x, y, D));
1411 * Save the unshuffled grid in aux.
1417 solution = snewn(w * h + 1, char);
1418 for (i = 0; i < w * h; i++)
1419 solution[i] = "0123456789abcdef"[tiles[i] & 0xF];
1420 solution[w*h] = '\0';
1426 * Now shuffle the grid.
1428 * In order to avoid accidentally generating an already-solved
1429 * grid, we will reshuffle as necessary to ensure that at least
1430 * one edge has a mismatched connection.
1432 * This can always be done, since validate_params() enforces a
1433 * grid area of at least 2 and our generator never creates
1434 * either type of rotationally invariant tile (cross and
1435 * blank). Hence there must be at least one edge separating
1436 * distinct tiles, and it must be possible to find orientations
1437 * of those tiles such that one tile is trying to connect
1438 * through that edge and the other is not.
1440 * (We could be more subtle, and allow the shuffle to generate
1441 * a grid in which all tiles match up locally and the only
1442 * criterion preventing the grid from being already solved is
1443 * connectedness. However, that would take more effort, and
1444 * it's easier to simply make sure every grid is _obviously_
1447 * We also require that our shuffle produces no loops in the
1448 * initial grid state, because it's a bit rude to light up a 'HEY,
1449 * YOU DID SOMETHING WRONG!' indicator when the user hasn't even
1450 * had a chance to do _anything_ yet. This also is possible just
1451 * by retrying the whole shuffle on failure, because it's clear
1452 * that at least one non-solved shuffle with no loops must exist.
1453 * (Proof: take the _solved_ state of the puzzle, and rotate one
1457 int mismatches, prev_loopsquares, this_loopsquares, i;
1461 for (y = 0; y < h; y++) {
1462 for (x = 0; x < w; x++) {
1463 int orig = index(params, tiles, x, y);
1464 int rot = random_upto(rs, 4);
1465 index(params, tiles, x, y) = ROT(orig, rot);
1470 * Check for loops, and try to fix them by reshuffling just
1471 * the squares involved.
1473 prev_loopsquares = w*h+1;
1475 loops = compute_loops_inner(w, h, params->wrapping, tiles, NULL);
1476 this_loopsquares = 0;
1477 for (i = 0; i < w*h; i++) {
1479 int orig = tiles[i];
1480 int rot = random_upto(rs, 4);
1481 tiles[i] = ROT(orig, rot);
1486 if (this_loopsquares > prev_loopsquares) {
1488 * We're increasing rather than reducing the number of
1489 * loops. Give up and go back to the full shuffle.
1493 if (this_loopsquares == 0)
1495 prev_loopsquares = this_loopsquares;
1500 * I can't even be bothered to check for mismatches across
1501 * a wrapping edge, so I'm just going to enforce that there
1502 * must be a mismatch across a non-wrapping edge, which is
1503 * still always possible.
1505 for (y = 0; y < h; y++) for (x = 0; x < w; x++) {
1506 if (x+1 < w && ((ROT(index(params, tiles, x, y), 2) ^
1507 index(params, tiles, x+1, y)) & L))
1509 if (y+1 < h && ((ROT(index(params, tiles, x, y), 2) ^
1510 index(params, tiles, x, y+1)) & U))
1514 if (mismatches == 0)
1522 * And now choose barrier locations. (We carefully do this
1523 * _after_ shuffling, so that changing the barrier rate in the
1524 * params while keeping the random seed the same will give the
1525 * same shuffled grid and _only_ change the barrier locations.
1526 * Also the way we choose barrier locations, by repeatedly
1527 * choosing one possibility from the list until we have enough,
1528 * is designed to ensure that raising the barrier rate while
1529 * keeping the seed the same will provide a superset of the
1530 * previous barrier set - i.e. if you ask for 10 barriers, and
1531 * then decide that's still too hard and ask for 20, you'll get
1532 * the original 10 plus 10 more, rather than getting 20 new
1533 * ones and the chance of remembering your first 10.)
1535 nbarriers = (int)(params->barrier_probability * count234(barriertree));
1536 assert(nbarriers >= 0 && nbarriers <= count234(barriertree));
1538 while (nbarriers > 0) {
1541 int x1, y1, d1, x2, y2, d2;
1544 * Extract a randomly chosen barrier from the list.
1546 i = random_upto(rs, count234(barriertree));
1547 xyd = delpos234(barriertree, i);
1549 assert(xyd != NULL);
1553 d1 = xyd->direction;
1556 OFFSET(x2, y2, x1, y1, d1, params);
1559 index(params, barriers, x1, y1) |= d1;
1560 index(params, barriers, x2, y2) |= d2;
1566 * Clean up the rest of the barrier list.
1571 while ( (xyd = delpos234(barriertree, 0)) != NULL)
1574 freetree234(barriertree);
1578 * Finally, encode the grid into a string game description.
1580 * My syntax is extremely simple: each square is encoded as a
1581 * hex digit in which bit 0 means a connection on the right,
1582 * bit 1 means up, bit 2 left and bit 3 down. (i.e. the same
1583 * encoding as used internally). Each digit is followed by
1584 * optional barrier indicators: `v' means a vertical barrier to
1585 * the right of it, and `h' means a horizontal barrier below
1588 desc = snewn(w * h * 3 + 1, char);
1590 for (y = 0; y < h; y++) {
1591 for (x = 0; x < w; x++) {
1592 *p++ = "0123456789abcdef"[index(params, tiles, x, y)];
1593 if ((params->wrapping || x < w-1) &&
1594 (index(params, barriers, x, y) & R))
1596 if ((params->wrapping || y < h-1) &&
1597 (index(params, barriers, x, y) & D))
1601 assert(p - desc <= w*h*3);
1610 static char *validate_desc(const game_params *params, const char *desc)
1612 int w = params->width, h = params->height;
1615 for (i = 0; i < w*h; i++) {
1616 if (*desc >= '0' && *desc <= '9')
1618 else if (*desc >= 'a' && *desc <= 'f')
1620 else if (*desc >= 'A' && *desc <= 'F')
1623 return "Game description shorter than expected";
1625 return "Game description contained unexpected character";
1627 while (*desc == 'h' || *desc == 'v')
1631 return "Game description longer than expected";
1636 /* ----------------------------------------------------------------------
1637 * Construct an initial game state, given a description and parameters.
1640 static game_state *new_game(midend *me, const game_params *params,
1646 assert(params->width > 0 && params->height > 0);
1647 assert(params->width > 1 || params->height > 1);
1650 * Create a blank game state.
1652 state = snew(game_state);
1653 w = state->width = params->width;
1654 h = state->height = params->height;
1655 state->wrapping = params->wrapping;
1656 state->last_rotate_dir = state->last_rotate_x = state->last_rotate_y = 0;
1657 state->completed = state->used_solve = FALSE;
1658 state->tiles = snewn(state->width * state->height, unsigned char);
1659 memset(state->tiles, 0, state->width * state->height);
1660 state->barriers = snewn(state->width * state->height, unsigned char);
1661 memset(state->barriers, 0, state->width * state->height);
1664 * Parse the game description into the grid.
1666 for (y = 0; y < h; y++) {
1667 for (x = 0; x < w; x++) {
1668 if (*desc >= '0' && *desc <= '9')
1669 tile(state, x, y) = *desc - '0';
1670 else if (*desc >= 'a' && *desc <= 'f')
1671 tile(state, x, y) = *desc - 'a' + 10;
1672 else if (*desc >= 'A' && *desc <= 'F')
1673 tile(state, x, y) = *desc - 'A' + 10;
1676 while (*desc == 'h' || *desc == 'v') {
1683 OFFSET(x2, y2, x, y, d1, state);
1686 barrier(state, x, y) |= d1;
1687 barrier(state, x2, y2) |= d2;
1695 * Set up border barriers if this is a non-wrapping game.
1697 if (!state->wrapping) {
1698 for (x = 0; x < state->width; x++) {
1699 barrier(state, x, 0) |= U;
1700 barrier(state, x, state->height-1) |= D;
1702 for (y = 0; y < state->height; y++) {
1703 barrier(state, 0, y) |= L;
1704 barrier(state, state->width-1, y) |= R;
1708 * We check whether this is de-facto a non-wrapping game
1709 * despite the parameters, in case we were passed the
1710 * description of a non-wrapping game. This is so that we
1711 * can change some aspects of the UI behaviour.
1713 state->wrapping = FALSE;
1714 for (x = 0; x < state->width; x++)
1715 if (!(barrier(state, x, 0) & U) ||
1716 !(barrier(state, x, state->height-1) & D))
1717 state->wrapping = TRUE;
1718 for (y = 0; y < state->height; y++)
1719 if (!(barrier(state, 0, y) & L) ||
1720 !(barrier(state, state->width-1, y) & R))
1721 state->wrapping = TRUE;
1727 static game_state *dup_game(const game_state *state)
1731 ret = snew(game_state);
1732 ret->width = state->width;
1733 ret->height = state->height;
1734 ret->wrapping = state->wrapping;
1735 ret->completed = state->completed;
1736 ret->used_solve = state->used_solve;
1737 ret->last_rotate_dir = state->last_rotate_dir;
1738 ret->last_rotate_x = state->last_rotate_x;
1739 ret->last_rotate_y = state->last_rotate_y;
1740 ret->tiles = snewn(state->width * state->height, unsigned char);
1741 memcpy(ret->tiles, state->tiles, state->width * state->height);
1742 ret->barriers = snewn(state->width * state->height, unsigned char);
1743 memcpy(ret->barriers, state->barriers, state->width * state->height);
1748 static void free_game(game_state *state)
1750 sfree(state->tiles);
1751 sfree(state->barriers);
1755 static char *solve_game(const game_state *state, const game_state *currstate,
1756 const char *aux, char **error)
1758 unsigned char *tiles;
1760 int retlen, retsize;
1763 tiles = snewn(state->width * state->height, unsigned char);
1767 * Run the internal solver on the provided grid. This might
1768 * not yield a complete solution.
1772 memcpy(tiles, state->tiles, state->width * state->height);
1773 solver_result = net_solver(state->width, state->height, tiles,
1774 state->barriers, state->wrapping);
1776 if (solver_result < 0) {
1777 *error = "No solution exists for this puzzle";
1782 for (i = 0; i < state->width * state->height; i++) {
1785 if (c >= '0' && c <= '9')
1787 else if (c >= 'a' && c <= 'f')
1788 tiles[i] = c - 'a' + 10;
1789 else if (c >= 'A' && c <= 'F')
1790 tiles[i] = c - 'A' + 10;
1797 * Now construct a string which can be passed to execute_move()
1798 * to transform the current grid into the solved one.
1801 ret = snewn(retsize, char);
1803 ret[retlen++] = 'S';
1805 for (i = 0; i < state->width * state->height; i++) {
1806 int from = currstate->tiles[i], to = tiles[i];
1807 int ft = from & (R|L|U|D), tt = to & (R|L|U|D);
1808 int x = i % state->width, y = i / state->width;
1810 char buf[80], *p = buf;
1813 continue; /* nothing needs doing at all */
1816 * To transform this tile into the desired tile: first
1817 * unlock the tile if it's locked, then rotate it if
1818 * necessary, then lock it if necessary.
1821 p += sprintf(p, ";L%d,%d", x, y);
1825 else if (tt == C(ft))
1827 else if (tt == F(ft))
1834 p += sprintf(p, ";%c%d,%d", chr, x, y);
1837 p += sprintf(p, ";L%d,%d", x, y);
1840 if (retlen + (p - buf) >= retsize) {
1841 retsize = retlen + (p - buf) + 512;
1842 ret = sresize(ret, retsize, char);
1844 memcpy(ret+retlen, buf, p - buf);
1849 assert(retlen < retsize);
1851 ret = sresize(ret, retlen+1, char);
1858 static int game_can_format_as_text_now(const game_params *params)
1863 static char *game_text_format(const game_state *state)
1868 /* ----------------------------------------------------------------------
1873 * Compute which squares are reachable from the centre square, as a
1874 * quick visual aid to determining how close the game is to
1875 * completion. This is also a simple way to tell if the game _is_
1876 * completed - just call this function and see whether every square
1879 static unsigned char *compute_active(const game_state *state, int cx, int cy)
1881 unsigned char *active;
1885 active = snewn(state->width * state->height, unsigned char);
1886 memset(active, 0, state->width * state->height);
1889 * We only store (x,y) pairs in todo, but it's easier to reuse
1890 * xyd_cmp and just store direction 0 every time.
1892 todo = newtree234(xyd_cmp_nc);
1893 index(state, active, cx, cy) = ACTIVE;
1894 add234(todo, new_xyd(cx, cy, 0));
1896 while ( (xyd = delpos234(todo, 0)) != NULL) {
1897 int x1, y1, d1, x2, y2, d2;
1903 for (d1 = 1; d1 < 0x10; d1 <<= 1) {
1904 OFFSET(x2, y2, x1, y1, d1, state);
1908 * If the next tile in this direction is connected to
1909 * us, and there isn't a barrier in the way, and it
1910 * isn't already marked active, then mark it active and
1911 * add it to the to-examine list.
1913 if ((tile(state, x1, y1) & d1) &&
1914 (tile(state, x2, y2) & d2) &&
1915 !(barrier(state, x1, y1) & d1) &&
1916 !index(state, active, x2, y2)) {
1917 index(state, active, x2, y2) = ACTIVE;
1918 add234(todo, new_xyd(x2, y2, 0));
1922 /* Now we expect the todo list to have shrunk to zero size. */
1923 assert(count234(todo) == 0);
1929 struct net_neighbour_ctx {
1931 const unsigned char *tiles, *barriers;
1932 int i, n, neighbours[4];
1934 static int net_neighbour(int vertex, void *vctx)
1936 struct net_neighbour_ctx *ctx = (struct net_neighbour_ctx *)vctx;
1939 int x = vertex % ctx->w, y = vertex / ctx->w;
1940 int tile, dir, x1, y1, v1;
1942 ctx->i = ctx->n = 0;
1944 tile = ctx->tiles[vertex];
1946 tile &= ~ctx->barriers[vertex];
1948 for (dir = 1; dir < 0x10; dir <<= 1) {
1951 OFFSETWH(x1, y1, x, y, dir, ctx->w, ctx->h);
1952 v1 = y1 * ctx->w + x1;
1953 if (ctx->tiles[v1] & F(dir))
1954 ctx->neighbours[ctx->n++] = v1;
1958 if (ctx->i < ctx->n)
1959 return ctx->neighbours[ctx->i++];
1964 static int *compute_loops_inner(int w, int h, int wrapping,
1965 const unsigned char *tiles,
1966 const unsigned char *barriers)
1968 struct net_neighbour_ctx ctx;
1969 struct findloopstate *fls;
1973 fls = findloop_new_state(w*h);
1977 ctx.barriers = barriers;
1978 findloop_run(fls, w*h, net_neighbour, &ctx);
1980 loops = snewn(w*h, int);
1982 for (y = 0; y < h; y++) {
1983 for (x = 0; x < w; x++) {
1987 for (dir = 1; dir < 0x10; dir <<= 1) {
1988 if ((tiles[y*w+x] & dir) &&
1989 !(barriers && (barriers[y*w+x] & dir))) {
1990 OFFSETWH(x1, y1, x, y, dir, w, h);
1991 if ((tiles[y1*w+x1] & F(dir)) &&
1992 findloop_is_loop_edge(fls, y*w+x, y1*w+x1))
1996 loops[y*w+x] = flags;
2000 findloop_free_state(fls);
2004 static int *compute_loops(const game_state *state)
2006 return compute_loops_inner(state->width, state->height, state->wrapping,
2007 state->tiles, state->barriers);
2011 int org_x, org_y; /* origin */
2012 int cx, cy; /* source tile (game coordinates) */
2015 random_state *rs; /* used for jumbling */
2017 int dragtilex, dragtiley, dragstartx, dragstarty, dragged;
2021 static game_ui *new_ui(const game_state *state)
2025 game_ui *ui = snew(game_ui);
2026 ui->org_x = ui->org_y = 0;
2027 ui->cur_x = ui->cx = state->width / 2;
2028 ui->cur_y = ui->cy = state->height / 2;
2029 ui->cur_visible = FALSE;
2030 get_random_seed(&seed, &seedsize);
2031 ui->rs = random_new(seed, seedsize);
2037 static void free_ui(game_ui *ui)
2039 random_free(ui->rs);
2043 static char *encode_ui(const game_ui *ui)
2047 * We preserve the origin and centre-point coordinates over a
2050 sprintf(buf, "O%d,%d;C%d,%d", ui->org_x, ui->org_y, ui->cx, ui->cy);
2054 static void decode_ui(game_ui *ui, const char *encoding)
2056 sscanf(encoding, "O%d,%d;C%d,%d",
2057 &ui->org_x, &ui->org_y, &ui->cx, &ui->cy);
2060 static void game_changed_state(game_ui *ui, const game_state *oldstate,
2061 const game_state *newstate)
2065 struct game_drawstate {
2073 /* ----------------------------------------------------------------------
2076 static char *interpret_move(const game_state *state, game_ui *ui,
2077 const game_drawstate *ds,
2078 int x, int y, int button)
2081 int tx = -1, ty = -1, dir = 0;
2082 int shift = button & MOD_SHFT, ctrl = button & MOD_CTRL;
2084 NONE, ROTATE_LEFT, ROTATE_180, ROTATE_RIGHT, TOGGLE_LOCK, JUMBLE,
2085 MOVE_ORIGIN, MOVE_SOURCE, MOVE_ORIGIN_AND_SOURCE, MOVE_CURSOR
2088 button &= ~MOD_MASK;
2092 if (button == LEFT_BUTTON ||
2093 button == MIDDLE_BUTTON ||
2095 button == LEFT_DRAG ||
2096 button == LEFT_RELEASE ||
2097 button == RIGHT_DRAG ||
2098 button == RIGHT_RELEASE ||
2100 button == RIGHT_BUTTON) {
2102 if (ui->cur_visible) {
2103 ui->cur_visible = FALSE;
2108 * The button must have been clicked on a valid tile.
2110 x -= WINDOW_OFFSET + TILE_BORDER;
2111 y -= WINDOW_OFFSET + TILE_BORDER;
2116 if (tx >= state->width || ty >= state->height)
2118 /* Transform from physical to game coords */
2119 tx = (tx + ui->org_x) % state->width;
2120 ty = (ty + ui->org_y) % state->height;
2121 if (x % TILE_SIZE >= TILE_SIZE - TILE_BORDER ||
2122 y % TILE_SIZE >= TILE_SIZE - TILE_BORDER)
2127 if (button == MIDDLE_BUTTON
2129 || button == RIGHT_BUTTON /* with a stylus, `right-click' locks */
2133 * Middle button never drags: it only toggles the lock.
2135 action = TOGGLE_LOCK;
2136 } else if (button == LEFT_BUTTON
2137 #ifndef STYLUS_BASED
2138 || button == RIGHT_BUTTON /* (see above) */
2142 * Otherwise, we note down the start point for a drag.
2146 ui->dragstartx = x % TILE_SIZE;
2147 ui->dragstarty = y % TILE_SIZE;
2148 ui->dragged = FALSE;
2149 return nullret; /* no actual action */
2150 } else if (button == LEFT_DRAG
2151 #ifndef STYLUS_BASED
2152 || button == RIGHT_DRAG
2156 * Find the new drag point and see if it necessitates a
2159 int x0,y0, xA,yA, xC,yC, xF,yF;
2161 int d0, dA, dC, dF, dmin;
2166 mx = x - (ui->dragtilex * TILE_SIZE);
2167 my = y - (ui->dragtiley * TILE_SIZE);
2169 x0 = ui->dragstartx;
2170 y0 = ui->dragstarty;
2171 xA = ui->dragstarty;
2172 yA = TILE_SIZE-1 - ui->dragstartx;
2173 xF = TILE_SIZE-1 - ui->dragstartx;
2174 yF = TILE_SIZE-1 - ui->dragstarty;
2175 xC = TILE_SIZE-1 - ui->dragstarty;
2176 yC = ui->dragstartx;
2178 d0 = (mx-x0)*(mx-x0) + (my-y0)*(my-y0);
2179 dA = (mx-xA)*(mx-xA) + (my-yA)*(my-yA);
2180 dF = (mx-xF)*(mx-xF) + (my-yF)*(my-yF);
2181 dC = (mx-xC)*(mx-xC) + (my-yC)*(my-yC);
2183 dmin = min(min(d0,dA),min(dF,dC));
2187 } else if (dF == dmin) {
2188 action = ROTATE_180;
2189 ui->dragstartx = xF;
2190 ui->dragstarty = yF;
2192 } else if (dA == dmin) {
2193 action = ROTATE_LEFT;
2194 ui->dragstartx = xA;
2195 ui->dragstarty = yA;
2197 } else /* dC == dmin */ {
2198 action = ROTATE_RIGHT;
2199 ui->dragstartx = xC;
2200 ui->dragstarty = yC;
2203 } else if (button == LEFT_RELEASE
2204 #ifndef STYLUS_BASED
2205 || button == RIGHT_RELEASE
2210 * There was a click but no perceptible drag:
2211 * revert to single-click behaviour.
2216 if (button == LEFT_RELEASE)
2217 action = ROTATE_LEFT;
2219 action = ROTATE_RIGHT;
2221 return nullret; /* no action */
2224 #else /* USE_DRAGGING */
2226 action = (button == LEFT_BUTTON ? ROTATE_LEFT :
2227 button == RIGHT_BUTTON ? ROTATE_RIGHT : TOGGLE_LOCK);
2229 #endif /* USE_DRAGGING */
2231 } else if (IS_CURSOR_MOVE(button)) {
2233 case CURSOR_UP: dir = U; break;
2234 case CURSOR_DOWN: dir = D; break;
2235 case CURSOR_LEFT: dir = L; break;
2236 case CURSOR_RIGHT: dir = R; break;
2237 default: return nullret;
2239 if (shift && ctrl) action = MOVE_ORIGIN_AND_SOURCE;
2240 else if (shift) action = MOVE_ORIGIN;
2241 else if (ctrl) action = MOVE_SOURCE;
2242 else action = MOVE_CURSOR;
2243 } else if (button == 'a' || button == 's' || button == 'd' ||
2244 button == 'A' || button == 'S' || button == 'D' ||
2245 button == 'f' || button == 'F' ||
2246 IS_CURSOR_SELECT(button)) {
2249 if (button == 'a' || button == 'A' || button == CURSOR_SELECT)
2250 action = ROTATE_LEFT;
2251 else if (button == 's' || button == 'S' || button == CURSOR_SELECT2)
2252 action = TOGGLE_LOCK;
2253 else if (button == 'd' || button == 'D')
2254 action = ROTATE_RIGHT;
2255 else if (button == 'f' || button == 'F')
2256 action = ROTATE_180;
2257 ui->cur_visible = TRUE;
2258 } else if (button == 'j' || button == 'J') {
2259 /* XXX should we have some mouse control for this? */
2265 * The middle button locks or unlocks a tile. (A locked tile
2266 * cannot be turned, and is visually marked as being locked.
2267 * This is a convenience for the player, so that once they are
2268 * sure which way round a tile goes, they can lock it and thus
2269 * avoid forgetting later on that they'd already done that one;
2270 * and the locking also prevents them turning the tile by
2271 * accident. If they change their mind, another middle click
2274 if (action == TOGGLE_LOCK) {
2276 sprintf(buf, "L%d,%d", tx, ty);
2278 } else if (action == ROTATE_LEFT || action == ROTATE_RIGHT ||
2279 action == ROTATE_180) {
2283 * The left and right buttons have no effect if clicked on a
2286 if (tile(state, tx, ty) & LOCKED)
2290 * Otherwise, turn the tile one way or the other. Left button
2291 * turns anticlockwise; right button turns clockwise.
2293 sprintf(buf, "%c%d,%d", (int)(action == ROTATE_LEFT ? 'A' :
2294 action == ROTATE_RIGHT ? 'C' : 'F'), tx, ty);
2296 } else if (action == JUMBLE) {
2298 * Jumble all unlocked tiles to random orientations.
2305 * Maximum string length assumes no int can be converted to
2306 * decimal and take more than 11 digits!
2308 maxlen = state->width * state->height * 25 + 3;
2310 ret = snewn(maxlen, char);
2314 for (jy = 0; jy < state->height; jy++) {
2315 for (jx = 0; jx < state->width; jx++) {
2316 if (!(tile(state, jx, jy) & LOCKED)) {
2317 int rot = random_upto(ui->rs, 4);
2319 p += sprintf(p, ";%c%d,%d", "AFC"[rot-1], jx, jy);
2325 assert(p - ret < maxlen);
2326 ret = sresize(ret, p - ret, char);
2329 } else if (action == MOVE_ORIGIN || action == MOVE_SOURCE ||
2330 action == MOVE_ORIGIN_AND_SOURCE || action == MOVE_CURSOR) {
2332 if (action == MOVE_ORIGIN || action == MOVE_ORIGIN_AND_SOURCE) {
2333 if (state->wrapping) {
2334 OFFSET(ui->org_x, ui->org_y, ui->org_x, ui->org_y, dir, state);
2335 } else return nullret; /* disallowed for non-wrapping grids */
2337 if (action == MOVE_SOURCE || action == MOVE_ORIGIN_AND_SOURCE) {
2338 OFFSET(ui->cx, ui->cy, ui->cx, ui->cy, dir, state);
2340 if (action == MOVE_CURSOR) {
2341 OFFSET(ui->cur_x, ui->cur_y, ui->cur_x, ui->cur_y, dir, state);
2342 ui->cur_visible = TRUE;
2350 static game_state *execute_move(const game_state *from, const char *move)
2353 int tx = -1, ty = -1, n, noanim, orig;
2355 ret = dup_game(from);
2357 if (move[0] == 'J' || move[0] == 'S') {
2359 ret->used_solve = TRUE;
2368 ret->last_rotate_dir = 0; /* suppress animation */
2369 ret->last_rotate_x = ret->last_rotate_y = 0;
2372 if ((move[0] == 'A' || move[0] == 'C' ||
2373 move[0] == 'F' || move[0] == 'L') &&
2374 sscanf(move+1, "%d,%d%n", &tx, &ty, &n) >= 2 &&
2375 tx >= 0 && tx < from->width && ty >= 0 && ty < from->height) {
2376 orig = tile(ret, tx, ty);
2377 if (move[0] == 'A') {
2378 tile(ret, tx, ty) = A(orig);
2380 ret->last_rotate_dir = +1;
2381 } else if (move[0] == 'F') {
2382 tile(ret, tx, ty) = F(orig);
2384 ret->last_rotate_dir = +2; /* + for sake of argument */
2385 } else if (move[0] == 'C') {
2386 tile(ret, tx, ty) = C(orig);
2388 ret->last_rotate_dir = -1;
2390 assert(move[0] == 'L');
2391 tile(ret, tx, ty) ^= LOCKED;
2395 if (*move == ';') move++;
2402 if (tx == -1 || ty == -1) { free_game(ret); return NULL; }
2403 ret->last_rotate_x = tx;
2404 ret->last_rotate_y = ty;
2408 * Check whether the game has been completed.
2410 * For this purpose it doesn't matter where the source square is,
2411 * because we can start from anywhere (or, at least, any square
2412 * that's non-empty!), and correctly determine whether the game is
2416 unsigned char *active;
2418 int complete = TRUE;
2420 for (pos = 0; pos < ret->width * ret->height; pos++)
2421 if (ret->tiles[pos] & 0xF)
2424 if (pos < ret->width * ret->height) {
2425 active = compute_active(ret, pos % ret->width, pos / ret->width);
2427 for (pos = 0; pos < ret->width * ret->height; pos++)
2428 if ((ret->tiles[pos] & 0xF) && !active[pos]) {
2437 ret->completed = TRUE;
2444 /* ----------------------------------------------------------------------
2445 * Routines for drawing the game position on the screen.
2448 static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
2450 game_drawstate *ds = snew(game_drawstate);
2453 ds->started = FALSE;
2454 ds->width = state->width;
2455 ds->height = state->height;
2456 ds->org_x = ds->org_y = -1;
2457 ds->visible = snewn(state->width * state->height, int);
2458 ds->tilesize = 0; /* undecided yet */
2459 for (i = 0; i < state->width * state->height; i++)
2460 ds->visible[i] = -1;
2465 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
2471 static void game_compute_size(const game_params *params, int tilesize,
2474 *x = WINDOW_OFFSET * 2 + tilesize * params->width + TILE_BORDER;
2475 *y = WINDOW_OFFSET * 2 + tilesize * params->height + TILE_BORDER;
2478 static void game_set_size(drawing *dr, game_drawstate *ds,
2479 const game_params *params, int tilesize)
2481 ds->tilesize = tilesize;
2484 static float *game_colours(frontend *fe, int *ncolours)
2488 ret = snewn(NCOLOURS * 3, float);
2489 *ncolours = NCOLOURS;
2492 * Basic background colour is whatever the front end thinks is
2493 * a sensible default.
2495 frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
2500 ret[COL_WIRE * 3 + 0] = 0.0F;
2501 ret[COL_WIRE * 3 + 1] = 0.0F;
2502 ret[COL_WIRE * 3 + 2] = 0.0F;
2505 * Powered wires and powered endpoints are cyan.
2507 ret[COL_POWERED * 3 + 0] = 0.0F;
2508 ret[COL_POWERED * 3 + 1] = 1.0F;
2509 ret[COL_POWERED * 3 + 2] = 1.0F;
2514 ret[COL_BARRIER * 3 + 0] = 1.0F;
2515 ret[COL_BARRIER * 3 + 1] = 0.0F;
2516 ret[COL_BARRIER * 3 + 2] = 0.0F;
2519 * Highlighted loops are red as well.
2521 ret[COL_LOOP * 3 + 0] = 1.0F;
2522 ret[COL_LOOP * 3 + 1] = 0.0F;
2523 ret[COL_LOOP * 3 + 2] = 0.0F;
2526 * Unpowered endpoints are blue.
2528 ret[COL_ENDPOINT * 3 + 0] = 0.0F;
2529 ret[COL_ENDPOINT * 3 + 1] = 0.0F;
2530 ret[COL_ENDPOINT * 3 + 2] = 1.0F;
2533 * Tile borders are a darker grey than the background.
2535 ret[COL_BORDER * 3 + 0] = 0.5F * ret[COL_BACKGROUND * 3 + 0];
2536 ret[COL_BORDER * 3 + 1] = 0.5F * ret[COL_BACKGROUND * 3 + 1];
2537 ret[COL_BORDER * 3 + 2] = 0.5F * ret[COL_BACKGROUND * 3 + 2];
2540 * Locked tiles are a grey in between those two.
2542 ret[COL_LOCKED * 3 + 0] = 0.75F * ret[COL_BACKGROUND * 3 + 0];
2543 ret[COL_LOCKED * 3 + 1] = 0.75F * ret[COL_BACKGROUND * 3 + 1];
2544 ret[COL_LOCKED * 3 + 2] = 0.75F * ret[COL_BACKGROUND * 3 + 2];
2549 static void draw_filled_line(drawing *dr, int x1, int y1, int x2, int y2,
2552 draw_line(dr, x1-1, y1, x2-1, y2, COL_WIRE);
2553 draw_line(dr, x1+1, y1, x2+1, y2, COL_WIRE);
2554 draw_line(dr, x1, y1-1, x2, y2-1, COL_WIRE);
2555 draw_line(dr, x1, y1+1, x2, y2+1, COL_WIRE);
2556 draw_line(dr, x1, y1, x2, y2, colour);
2559 static void draw_rect_coords(drawing *dr, int x1, int y1, int x2, int y2,
2562 int mx = (x1 < x2 ? x1 : x2);
2563 int my = (y1 < y2 ? y1 : y2);
2564 int dx = (x2 + x1 - 2*mx + 1);
2565 int dy = (y2 + y1 - 2*my + 1);
2567 draw_rect(dr, mx, my, dx, dy, colour);
2571 * draw_barrier_corner() and draw_barrier() are passed physical coords
2573 static void draw_barrier_corner(drawing *dr, game_drawstate *ds,
2574 int x, int y, int dx, int dy, int phase)
2576 int bx = WINDOW_OFFSET + TILE_SIZE * x;
2577 int by = WINDOW_OFFSET + TILE_SIZE * y;
2580 x1 = (dx > 0 ? TILE_SIZE+TILE_BORDER-1 : 0);
2581 y1 = (dy > 0 ? TILE_SIZE+TILE_BORDER-1 : 0);
2584 draw_rect_coords(dr, bx+x1+dx, by+y1,
2585 bx+x1-TILE_BORDER*dx, by+y1-(TILE_BORDER-1)*dy,
2587 draw_rect_coords(dr, bx+x1, by+y1+dy,
2588 bx+x1-(TILE_BORDER-1)*dx, by+y1-TILE_BORDER*dy,
2591 draw_rect_coords(dr, bx+x1, by+y1,
2592 bx+x1-(TILE_BORDER-1)*dx, by+y1-(TILE_BORDER-1)*dy,
2597 static void draw_barrier(drawing *dr, game_drawstate *ds,
2598 int x, int y, int dir, int phase)
2600 int bx = WINDOW_OFFSET + TILE_SIZE * x;
2601 int by = WINDOW_OFFSET + TILE_SIZE * y;
2604 x1 = (X(dir) > 0 ? TILE_SIZE : X(dir) == 0 ? TILE_BORDER : 0);
2605 y1 = (Y(dir) > 0 ? TILE_SIZE : Y(dir) == 0 ? TILE_BORDER : 0);
2606 w = (X(dir) ? TILE_BORDER : TILE_SIZE - TILE_BORDER);
2607 h = (Y(dir) ? TILE_BORDER : TILE_SIZE - TILE_BORDER);
2610 draw_rect(dr, bx+x1-X(dir), by+y1-Y(dir), w, h, COL_WIRE);
2612 draw_rect(dr, bx+x1, by+y1, w, h, COL_BARRIER);
2617 * draw_tile() is passed physical coordinates
2619 static void draw_tile(drawing *dr, const game_state *state, game_drawstate *ds,
2620 int x, int y, int tile, int src, float angle, int cursor)
2622 int bx = WINDOW_OFFSET + TILE_SIZE * x;
2623 int by = WINDOW_OFFSET + TILE_SIZE * y;
2625 float cx, cy, ex, ey, tx, ty;
2626 int dir, col, phase;
2629 * When we draw a single tile, we must draw everything up to
2630 * and including the borders around the tile. This means that
2631 * if the neighbouring tiles have connections to those borders,
2632 * we must draw those connections on the borders themselves.
2635 clip(dr, bx, by, TILE_SIZE+TILE_BORDER, TILE_SIZE+TILE_BORDER);
2638 * So. First blank the tile out completely: draw a big
2639 * rectangle in border colour, and a smaller rectangle in
2640 * background colour to fill it in.
2642 draw_rect(dr, bx, by, TILE_SIZE+TILE_BORDER, TILE_SIZE+TILE_BORDER,
2644 draw_rect(dr, bx+TILE_BORDER, by+TILE_BORDER,
2645 TILE_SIZE-TILE_BORDER, TILE_SIZE-TILE_BORDER,
2646 tile & LOCKED ? COL_LOCKED : COL_BACKGROUND);
2649 * Draw an inset outline rectangle as a cursor, in whichever of
2650 * COL_LOCKED and COL_BACKGROUND we aren't currently drawing
2654 draw_line(dr, bx+TILE_SIZE/8, by+TILE_SIZE/8,
2655 bx+TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
2656 tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
2657 draw_line(dr, bx+TILE_SIZE/8, by+TILE_SIZE/8,
2658 bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE/8,
2659 tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
2660 draw_line(dr, bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE/8,
2661 bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
2662 tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
2663 draw_line(dr, bx+TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
2664 bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
2665 tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
2669 * Set up the rotation matrix.
2671 matrix[0] = (float)cos(angle * PI / 180.0);
2672 matrix[1] = (float)-sin(angle * PI / 180.0);
2673 matrix[2] = (float)sin(angle * PI / 180.0);
2674 matrix[3] = (float)cos(angle * PI / 180.0);
2679 cx = cy = TILE_BORDER + (TILE_SIZE-TILE_BORDER) / 2.0F - 0.5F;
2680 col = (tile & ACTIVE ? COL_POWERED : COL_WIRE);
2681 for (dir = 1; dir < 0x10; dir <<= 1) {
2683 ex = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * X(dir);
2684 ey = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * Y(dir);
2685 MATMUL(tx, ty, matrix, ex, ey);
2686 draw_filled_line(dr, bx+(int)cx, by+(int)cy,
2687 bx+(int)(cx+tx), by+(int)(cy+ty),
2691 for (dir = 1; dir < 0x10; dir <<= 1) {
2693 ex = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * X(dir);
2694 ey = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * Y(dir);
2695 MATMUL(tx, ty, matrix, ex, ey);
2696 draw_line(dr, bx+(int)cx, by+(int)cy,
2697 bx+(int)(cx+tx), by+(int)(cy+ty),
2698 (tile & LOOP(dir)) ? COL_LOOP : col);
2701 /* If we've drawn any loop-highlighted arms, make sure the centre
2702 * point is loop-coloured rather than a later arm overwriting it. */
2703 if (tile & (RLOOP | ULOOP | LLOOP | DLOOP))
2704 draw_rect(dr, bx+(int)cx, by+(int)cy, 1, 1, COL_LOOP);
2707 * Draw the box in the middle. We do this in blue if the tile
2708 * is an unpowered endpoint, in cyan if the tile is a powered
2709 * endpoint, in black if the tile is the centrepiece, and
2710 * otherwise not at all.
2715 else if (COUNT(tile) == 1) {
2716 col = (tile & ACTIVE ? COL_POWERED : COL_ENDPOINT);
2721 points[0] = +1; points[1] = +1;
2722 points[2] = +1; points[3] = -1;
2723 points[4] = -1; points[5] = -1;
2724 points[6] = -1; points[7] = +1;
2726 for (i = 0; i < 8; i += 2) {
2727 ex = (TILE_SIZE * 0.24F) * points[i];
2728 ey = (TILE_SIZE * 0.24F) * points[i+1];
2729 MATMUL(tx, ty, matrix, ex, ey);
2730 points[i] = bx+(int)(cx+tx);
2731 points[i+1] = by+(int)(cy+ty);
2734 draw_polygon(dr, points, 4, col, COL_WIRE);
2738 * Draw the points on the border if other tiles are connected
2741 for (dir = 1; dir < 0x10; dir <<= 1) {
2742 int dx, dy, px, py, lx, ly, vx, vy, ox, oy;
2750 if (ox < 0 || ox >= state->width || oy < 0 || oy >= state->height)
2753 if (!(tile(state, GX(ox), GY(oy)) & F(dir)))
2756 px = bx + (int)(dx>0 ? TILE_SIZE + TILE_BORDER - 1 : dx<0 ? 0 : cx);
2757 py = by + (int)(dy>0 ? TILE_SIZE + TILE_BORDER - 1 : dy<0 ? 0 : cy);
2758 lx = dx * (TILE_BORDER-1);
2759 ly = dy * (TILE_BORDER-1);
2763 if (angle == 0.0 && (tile & dir)) {
2765 * If we are fully connected to the other tile, we must
2766 * draw right across the tile border. (We can use our
2767 * own ACTIVE state to determine what colour to do this
2768 * in: if we are fully connected to the other tile then
2769 * the two ACTIVE states will be the same.)
2771 draw_rect_coords(dr, px-vx, py-vy, px+lx+vx, py+ly+vy, COL_WIRE);
2772 draw_rect_coords(dr, px, py, px+lx, py+ly,
2773 ((tile & LOOP(dir)) ? COL_LOOP :
2774 (tile & ACTIVE) ? COL_POWERED :
2778 * The other tile extends into our border, but isn't
2779 * actually connected to us. Just draw a single black
2782 draw_rect_coords(dr, px, py, px, py, COL_WIRE);
2787 * Draw barrier corners, and then barriers.
2789 for (phase = 0; phase < 2; phase++) {
2790 for (dir = 1; dir < 0x10; dir <<= 1) {
2791 int x1, y1, corner = FALSE;
2793 * If at least one barrier terminates at the corner
2794 * between dir and A(dir), draw a barrier corner.
2796 if (barrier(state, GX(x), GY(y)) & (dir | A(dir))) {
2800 * Only count barriers terminating at this corner
2801 * if they're physically next to the corner. (That
2802 * is, if they've wrapped round from the far side
2803 * of the screen, they don't count.)
2807 if (x1 >= 0 && x1 < state->width &&
2808 y1 >= 0 && y1 < state->height &&
2809 (barrier(state, GX(x1), GY(y1)) & A(dir))) {
2814 if (x1 >= 0 && x1 < state->width &&
2815 y1 >= 0 && y1 < state->height &&
2816 (barrier(state, GX(x1), GY(y1)) & dir))
2823 * At least one barrier terminates here. Draw a
2826 draw_barrier_corner(dr, ds, x, y,
2827 X(dir)+X(A(dir)), Y(dir)+Y(A(dir)),
2832 for (dir = 1; dir < 0x10; dir <<= 1)
2833 if (barrier(state, GX(x), GY(y)) & dir)
2834 draw_barrier(dr, ds, x, y, dir, phase);
2839 draw_update(dr, bx, by, TILE_SIZE+TILE_BORDER, TILE_SIZE+TILE_BORDER);
2842 static void game_redraw(drawing *dr, game_drawstate *ds,
2843 const game_state *oldstate, const game_state *state,
2844 int dir, const game_ui *ui,
2847 int x, y, tx, ty, frame, last_rotate_dir, moved_origin = FALSE;
2848 unsigned char *active;
2853 * Clear the screen, and draw the exterior barrier lines, if
2854 * this is our first call or if the origin has changed.
2856 if (!ds->started || ui->org_x != ds->org_x || ui->org_y != ds->org_y) {
2862 WINDOW_OFFSET * 2 + TILE_SIZE * state->width + TILE_BORDER,
2863 WINDOW_OFFSET * 2 + TILE_SIZE * state->height + TILE_BORDER,
2866 ds->org_x = ui->org_x;
2867 ds->org_y = ui->org_y;
2868 moved_origin = TRUE;
2870 draw_update(dr, 0, 0,
2871 WINDOW_OFFSET*2 + TILE_SIZE*state->width + TILE_BORDER,
2872 WINDOW_OFFSET*2 + TILE_SIZE*state->height + TILE_BORDER);
2874 for (phase = 0; phase < 2; phase++) {
2876 for (x = 0; x < ds->width; x++) {
2877 if (x+1 < ds->width) {
2878 if (barrier(state, GX(x), GY(0)) & R)
2879 draw_barrier_corner(dr, ds, x, -1, +1, +1, phase);
2880 if (barrier(state, GX(x), GY(ds->height-1)) & R)
2881 draw_barrier_corner(dr, ds, x, ds->height, +1, -1, phase);
2883 if (barrier(state, GX(x), GY(0)) & U) {
2884 draw_barrier_corner(dr, ds, x, -1, -1, +1, phase);
2885 draw_barrier_corner(dr, ds, x, -1, +1, +1, phase);
2886 draw_barrier(dr, ds, x, -1, D, phase);
2888 if (barrier(state, GX(x), GY(ds->height-1)) & D) {
2889 draw_barrier_corner(dr, ds, x, ds->height, -1, -1, phase);
2890 draw_barrier_corner(dr, ds, x, ds->height, +1, -1, phase);
2891 draw_barrier(dr, ds, x, ds->height, U, phase);
2895 for (y = 0; y < ds->height; y++) {
2896 if (y+1 < ds->height) {
2897 if (barrier(state, GX(0), GY(y)) & D)
2898 draw_barrier_corner(dr, ds, -1, y, +1, +1, phase);
2899 if (barrier(state, GX(ds->width-1), GY(y)) & D)
2900 draw_barrier_corner(dr, ds, ds->width, y, -1, +1, phase);
2902 if (barrier(state, GX(0), GY(y)) & L) {
2903 draw_barrier_corner(dr, ds, -1, y, +1, -1, phase);
2904 draw_barrier_corner(dr, ds, -1, y, +1, +1, phase);
2905 draw_barrier(dr, ds, -1, y, R, phase);
2907 if (barrier(state, GX(ds->width-1), GY(y)) & R) {
2908 draw_barrier_corner(dr, ds, ds->width, y, -1, -1, phase);
2909 draw_barrier_corner(dr, ds, ds->width, y, -1, +1, phase);
2910 draw_barrier(dr, ds, ds->width, y, L, phase);
2917 last_rotate_dir = dir==-1 ? oldstate->last_rotate_dir :
2918 state->last_rotate_dir;
2919 if (oldstate && (t < ROTATE_TIME) && last_rotate_dir) {
2921 * We're animating a single tile rotation. Find the turning
2924 tx = (dir==-1 ? oldstate->last_rotate_x : state->last_rotate_x);
2925 ty = (dir==-1 ? oldstate->last_rotate_y : state->last_rotate_y);
2926 angle = last_rotate_dir * dir * 90.0F * (t / ROTATE_TIME);
2933 * We're animating a completion flash. Find which frame
2936 frame = (int)(ft / FLASH_FRAME);
2940 * Draw any tile which differs from the way it was last drawn.
2942 active = compute_active(state, ui->cx, ui->cy);
2943 loops = compute_loops(state);
2945 for (x = 0; x < ds->width; x++)
2946 for (y = 0; y < ds->height; y++) {
2947 int c = tile(state, GX(x), GY(y)) |
2948 index(state, active, GX(x), GY(y)) |
2949 index(state, loops, GX(x), GY(y));
2950 int is_src = GX(x) == ui->cx && GY(y) == ui->cy;
2951 int is_anim = GX(x) == tx && GY(y) == ty;
2952 int is_cursor = ui->cur_visible &&
2953 GX(x) == ui->cur_x && GY(y) == ui->cur_y;
2956 * In a completion flash, we adjust the LOCKED bit
2957 * depending on our distance from the centre point and
2961 int rcx = RX(ui->cx), rcy = RY(ui->cy);
2962 int xdist, ydist, dist;
2963 xdist = (x < rcx ? rcx - x : x - rcx);
2964 ydist = (y < rcy ? rcy - y : y - rcy);
2965 dist = (xdist > ydist ? xdist : ydist);
2967 if (frame >= dist && frame < dist+4) {
2968 int lock = (frame - dist) & 1;
2969 lock = lock ? LOCKED : 0;
2970 c = (c &~ LOCKED) | lock;
2975 index(state, ds->visible, x, y) != c ||
2976 index(state, ds->visible, x, y) == -1 ||
2977 is_src || is_anim || is_cursor) {
2978 draw_tile(dr, state, ds, x, y, c,
2979 is_src, (is_anim ? angle : 0.0F), is_cursor);
2980 if (is_src || is_anim || is_cursor)
2981 index(state, ds->visible, x, y) = -1;
2983 index(state, ds->visible, x, y) = c;
2988 * Update the status bar.
2991 char statusbuf[256], *p;
2993 int complete = FALSE;
2996 *p = '\0'; /* ensure even an empty status string is terminated */
2998 if (state->used_solve) {
2999 p += sprintf(p, "Auto-solved. ");
3001 } else if (state->completed) {
3002 p += sprintf(p, "COMPLETED! ");
3007 * Omit the 'Active: n/N' counter completely if the source
3008 * tile is a completely empty one, because then the active
3009 * count can't help but read '1'.
3011 if (tile(state, ui->cx, ui->cy) & 0xF) {
3012 n = state->width * state->height;
3013 for (i = a = n2 = 0; i < n; i++) {
3016 if (state->tiles[i] & 0xF)
3021 * Also, if we're displaying a completion indicator and
3022 * the game is still in its completed state (i.e. every
3023 * tile is active), we might as well omit this too.
3025 if (!complete || a < n2)
3026 p += sprintf(p, "Active: %d/%d", a, n2);
3029 status_bar(dr, statusbuf);
3036 static float game_anim_length(const game_state *oldstate,
3037 const game_state *newstate, int dir, game_ui *ui)
3039 int last_rotate_dir;
3042 * Don't animate if last_rotate_dir is zero.
3044 last_rotate_dir = dir==-1 ? oldstate->last_rotate_dir :
3045 newstate->last_rotate_dir;
3046 if (last_rotate_dir)
3052 static float game_flash_length(const game_state *oldstate,
3053 const game_state *newstate, int dir, game_ui *ui)
3056 * If the game has just been completed, we display a completion
3059 if (!oldstate->completed && newstate->completed &&
3060 !oldstate->used_solve && !newstate->used_solve) {
3062 if (size < newstate->width)
3063 size = newstate->width;
3064 if (size < newstate->height)
3065 size = newstate->height;
3066 return FLASH_FRAME * (size+4);
3072 static int game_status(const game_state *state)
3074 return state->completed ? +1 : 0;
3077 static int game_timing_state(const game_state *state, game_ui *ui)
3082 static void game_print_size(const game_params *params, float *x, float *y)
3087 * I'll use 8mm squares by default.
3089 game_compute_size(params, 800, &pw, &ph);
3094 static void draw_diagram(drawing *dr, game_drawstate *ds, int x, int y,
3095 int topleft, int v, int drawlines, int ink)
3097 int tx, ty, cx, cy, r, br, k, thick;
3099 tx = WINDOW_OFFSET + TILE_SIZE * x;
3100 ty = WINDOW_OFFSET + TILE_SIZE * y;
3103 * Find our centre point.
3106 cx = tx + (v & L ? TILE_SIZE / 4 : TILE_SIZE / 6);
3107 cy = ty + (v & U ? TILE_SIZE / 4 : TILE_SIZE / 6);
3109 br = TILE_SIZE / 32;
3111 cx = tx + TILE_SIZE / 2;
3112 cy = ty + TILE_SIZE / 2;
3119 * Draw the square block if we have an endpoint.
3121 if (v == 1 || v == 2 || v == 4 || v == 8)
3122 draw_rect(dr, cx - br, cy - br, br*2, br*2, ink);
3125 * Draw each radial line.
3128 for (k = 1; k < 16; k *= 2)
3130 int x1 = min(cx, cx + (r-thick) * X(k));
3131 int x2 = max(cx, cx + (r-thick) * X(k));
3132 int y1 = min(cy, cy + (r-thick) * Y(k));
3133 int y2 = max(cy, cy + (r-thick) * Y(k));
3134 draw_rect(dr, x1 - thick, y1 - thick,
3135 (x2 - x1) + 2*thick, (y2 - y1) + 2*thick, ink);
3140 static void game_print(drawing *dr, const game_state *state, int tilesize)
3142 int w = state->width, h = state->height;
3143 int ink = print_mono_colour(dr, 0);
3146 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
3147 game_drawstate ads, *ds = &ads;
3148 game_set_size(dr, ds, NULL, tilesize);
3153 print_line_width(dr, TILE_SIZE / (state->wrapping ? 128 : 12));
3154 draw_rect_outline(dr, WINDOW_OFFSET, WINDOW_OFFSET,
3155 TILE_SIZE * w, TILE_SIZE * h, ink);
3160 print_line_width(dr, TILE_SIZE / 128);
3161 for (x = 1; x < w; x++)
3162 draw_line(dr, WINDOW_OFFSET + TILE_SIZE * x, WINDOW_OFFSET,
3163 WINDOW_OFFSET + TILE_SIZE * x, WINDOW_OFFSET + TILE_SIZE * h,
3165 for (y = 1; y < h; y++)
3166 draw_line(dr, WINDOW_OFFSET, WINDOW_OFFSET + TILE_SIZE * y,
3167 WINDOW_OFFSET + TILE_SIZE * w, WINDOW_OFFSET + TILE_SIZE * y,
3173 for (y = 0; y <= h; y++)
3174 for (x = 0; x <= w; x++) {
3175 int b = barrier(state, x % w, y % h);
3176 if (x < w && (b & U))
3177 draw_rect(dr, WINDOW_OFFSET + TILE_SIZE * x - TILE_SIZE/24,
3178 WINDOW_OFFSET + TILE_SIZE * y - TILE_SIZE/24,
3179 TILE_SIZE + TILE_SIZE/24 * 2, TILE_SIZE/24 * 2, ink);
3180 if (y < h && (b & L))
3181 draw_rect(dr, WINDOW_OFFSET + TILE_SIZE * x - TILE_SIZE/24,
3182 WINDOW_OFFSET + TILE_SIZE * y - TILE_SIZE/24,
3183 TILE_SIZE/24 * 2, TILE_SIZE + TILE_SIZE/24 * 2, ink);
3189 for (y = 0; y < h; y++)
3190 for (x = 0; x < w; x++) {
3191 int vx, v = tile(state, x, y);
3192 int locked = v & LOCKED;
3197 * Rotate into a standard orientation for the top left
3201 while (vx != 0 && vx != 15 && vx != 1 && vx != 9 && vx != 13 &&
3206 * Draw the top left corner diagram.
3208 draw_diagram(dr, ds, x, y, TRUE, vx, TRUE, ink);
3211 * Draw the real solution diagram, if we're doing so.
3213 draw_diagram(dr, ds, x, y, FALSE, v, locked, ink);
3221 const struct game thegame = {
3222 "Net", "games.net", "net",
3224 game_fetch_preset, NULL,
3229 TRUE, game_configure, custom_params,
3237 FALSE, game_can_format_as_text_now, game_text_format,
3245 PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
3248 game_free_drawstate,
3253 TRUE, FALSE, game_print_size, game_print,
3254 TRUE, /* wants_statusbar */
3255 FALSE, game_timing_state,